MC908KX2MDWE Datasheet, PDF (34/210 Pages) Freescale Semiconductor, Inc – High-performance M68HC08 architecture, Fully upward-compatible object code with M6805, M146805, and M68HC05 Families

Memory
2.9 FLASH Program/Read Operation
Programming of the FLASH memory is done on a row basis. A row consists of 32 consecutive bytes
starting from addresses $XX00, $XX20, $XX40, $XX60, $XX80, $XXA0, $XXC0, and $XXE0. Use this
step-by-step procedure to program a row of FLASH memory (Figure 2-4 is a flowchart representation).
NOTE
Only bytes which are currently $FF may be programmed.
1. Set the PGM bit. This configures the memory for program operation and enables the latching of
address and data for programming.
2. Read the FLASH block protect register.
3. Write any data to any FLASH location within the address range desired.
4. Wait for a time, t_NVS (minimum 10 µs).
5. Set the HVEN bit.
6. Wait for a time, t_PGS (minimum 5 µs).
7. Write data to the FLASH address being programmed⁽¹⁾.
8. Wait for time, t_PROG (minimum 30 µs).
9. Repeat step 7 and 8 until all desired bytes within the row are programmed.
10. Clear the PGM bit⁽¹⁾.
11. Wait for time, t_NVH (minimum 5 µs).
12. Clear the HVEN bit.
13. After time, t_RCV (typical 1 µs), the memory can be accessed in read mode again.
This program sequence is repeated throughout the memory until all data is programmed.
NOTE
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order shown, other unrelated operations may
occur between the steps. Do not exceed t_PROG maximum. See 17.11
Memory Characteristics.
1. The time between each FLASH address change, or the time between the last FLASH address programmed to clearing
PGM bit, must not exceed the maximum programming time, t_PROG maximum.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
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